Flexible doctor or scraper blade



May 5, 1931.. J. w. VEDDER FLEXIBLE DOCTOR OR SCRAPER BLADE Filed Sept. 26, 1930 zhzi/ii a, ar-n4 Patented May 5, 1931 UNITED STATES PATENT OFFICE JOHN WARREN VEDDER, F WORCESTER, MASSACHUSETTS, ASSIGNOR T0 RICE, BARTON & FALES, INCORPORATED, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS FLEXIBLE DOCTOR OR SCRAPER BLADE Application filed September 26, 1930. Serial No. 484,523.

The object of this invention is to provide a new and improved doctor apparatus particularly adapted for use in connection with the calender and other rolls of a paper making machine.

The invention has particular reference to improving the apparatus shown in a joint application for patent filed by me and Frederick W. Lodding January 28, 1929, Serial No. 335,600. 1

In said prior application is shown a doctor apparatus consisting of a flexible blade rigidly secured at its rear end to a support, engaging which are one ormore spring blades 5 of shorter width resting on top of the scraper or doctor blade, the blades being held in place by screws threaded into the support, each screw carrying a non-circular block or washer.

By turning these blocksor washers in or out the desired degree and by tightening the screws the spring blade or blades and thereby the doctor blade can be adjusted so that the doctor blade can be accurately set to engage the roll at any point along its length. If in operation the doctor blade is found not to be in correct engagement with the periphery of the roll at any point along its length, the proper adjustment can be made by manipulating the particular block or washer controlling the point.

In making this adjustment, I have found that it is very desirable to limit the area of adjustment obtained by any particular screw and block so that when an adjustment is made it will be limited to the particular point.

To accomplish this desirable result, I provide the spring blade with slots extending backwardly from its front edge, to divide the same into sections separately engaging the doctor blade, each section being under the control of one of the adjusting devices.

By this improvement independent adjustments can be made along the length of the designates the support, which has a groove 11' along its front edge in which is placed the flexible scraper or doctor blade 12, which bears at its front edge 13 on the periphery of the calender roll 14:.

A flexible spring blade 15 is placed on top of the doctor blade 12 and the same is provided with slots 17 at its rear edge. The front edge of the spring blade 15 is. bent downwardly as shown at 19 so that the engagement between the spring blade and the doctor blade will be at the front edge thereof.

Screws 18 are threaded into the support 10 and the slots 17 in the blade'15 are positioned so that the blade 15 can be slid backwardly in place on the screws. Non-circular heads or washers 20 are placed under the screwheads and these washers may be swung to engage more or less forwardly on the spring blade 15.

The spring blade 15 is provided with slots 21 which extend backward about to the edge of the heads 20 when the same are set parallel with the roll, these slots being spaced equally along the length of the blade 15 between the slots 17.

By this arrangement, the spring blade is divided into sections, each section being under the control of a screw 18 and head 20. By this arrangement, when any head or washer is swung outwardly or inwardly and the screw is tightened to Vary the pressure of the spring blade down on the doctor blade, the adjustment will be confined practically to one of the sections of the spring blade. Hence the adjustment can be limited longitudinally of the doctor blade and by this construction very fine and accurate adjustment can be made at any point along the length of the doctor blade without having said adjustment extend to any degree to either side of the section.

By this improvement a very fine setting of the doctor blade can be made so that the same will very accurately engage the pe-' riphery of the doctor blade.

The details and arrangements herein shown and described may be greatly varied by a skilled mechanic without departing from the scope of my invention as expressed in the claims.

Having thus full described my invention, what I claim an desire to secure by Letters Patent is 1. The combination of a support, a scraper or doctor blade carried thereby, a spring blade on top of the doctor blade, said spring blade being provided with slots extending backwardly from its front edge to divide the same into sections separately engaging the doctor blade, and an adjusting or tightening device for each section.

2. The combination of a support, a scraper or doctor blade carried thereby, a spring blade on to of the doctor blade having its front edge ent down to engage the doctor blade, said spring blade being provided with slots extending backwardly from its front edge to divide the same into sections separately engaging the doctor blade, and an adjusting device or each section.

3. The combination of a support, a scraper or doctor blade carried thereby, a spring blade on top of the doctor blade, said spring blade being provided with slots extending backwardly from its front edge to divide the same into sections separatelyv engaging the doctor blade, and an adjusting or tightening device for each section comprising a screw and non-circular head.

4. The combination of a support, a scraper or doctor blade carried thereby, a spring blade on top of the doctor blade having slots on its back edge, screws threaded into the support and extending through said slots, and non-circular heads or washers on said screws, said spring blade being provided with slots extending backwardly from its front edge to divide the same into sections separately engaging the doctor blade.

5. The combination of a support, a scraper or doctor blade carried thereby, a spring blade on top of the doctor blade having slots on its back edge, screws threaded into the support and extending through said slots, and non-circular heads or washers on said screws, said spring blade being provided with slots extending backwardly from its front edge to divide the same into sections, the slots on the front edge of the spring blade being spaced equally between the slots on the rear edge of the spring blade.

In testimony whereof I have hereunto affixed my signature.

JOHN WARREN VEDDE-R. 

